HashMap n-dimensional using a recursive function

Question

I don't know how to make a matrix n dimensional using HashMap. The idea is to enter a number which indicates the dimension of the matrix and from this make a recursive function which creates the n-dimensional HashMap.

For example, if you want a 5 dimensional matrix, you have to do inside of it one with 4 dimensions, inside 3 dimensions and etc..

Answer 1

Map<List<Integer>, ValueType>

You can just fill your Lists that are used for the key of the map with N amount of numbers. Each number in your list specifies an offset of the dimension specified by the index of the number in your list. There is not much more to say, you can of course wrap it around and defend from "out of bounds" and such indefinite operations, which you determine.

Answer 2

I don't really understand why you need a recursive function for that (unless it's for learning purposes), but btw, here is what you should do :

1) The function will have 2 parameters : the current position + the dimension

2) If (position == dimension) then stop.

3) In the function, if (position == 0), create the array.

4) In all cases, create array[position] as a new HashMap

5) Call back the function with parameters (position+1, dimension)

Hope this helps